Patent GB-790043-A (GB)
Title: Hydrocarbon oil cracking process conducted with circulating reaction masses
IPC: C10G9/00
Filed: 1954-05-06
Abstract: Liquid hydrocarbons are converted to normally gaseous, partially unsaturated hydrocarbons by a process in which a granular heat-carrying mass is circulated through a closed system including a reaction zone, a re-heating zone and an elevating conduit, said mass being heated by indirect heat transfer in the reheating zone, a liquid hydrocarbon to be converted is applied to the heated mass and the heated mass is passed through the reaction zone at such a rate and at a temperature between 500 DEG  and 750 DEG  C. that the hydrocarbons are primarily converted to gaseous and minor quantities of liquid hydrocarbons which are conducted to a rectifying or gas separating device and are completely or partially discharged therefrom, the other part being used as a lifting gas, and secondarily to a coke layer on the mass and the mass is recirculated through the elevating conduit <PICT:0790043/IV (b)/1> by means of the lifting gas or by means of one or more components thereof.  The initial liquid hydrocarbon may be petroleum oil, a fraction of petroleum oil, a residual oil or a bituminous tar oil. The lifting gas may be ethane, propane, or butane.  In an example, coke of globular form and a size of 5-15 mms. diameter is circulated at a rate of 1-7 tons per hour at a temperature of 640 DEG  C. in a mixing zone, 110 kilograms of crude oil are injected per hour.  The temperature of the coke is thereby lowered by about 80 DEG  C.  After 30 minutes the coke is elevated by the reaction gases and is again brought to the initial temperature by indirect heating.  The gaseous products leave the reactor after a dwell time of 20 seconds, while the coke produced deposits on the circulating coke.  A suitable apparatus consists of a separator 6 from which the heat carrying mass passes through the heater 1 and is mixed at 8 with the preheated oil in the reactor 2.  Cracked gases leave through outlet 9 and are fractionated in the rectifier 16.  The saturated low hydrocarbons are returned to the cycle at 13 and the remainder withdrawn at 12.  The saturated low hydrocarbons may be used as the lifting medium where they are cracked in the tubular conduit 5 owing to contact with the hot coke to give unsaturated hydrocarbons such as ethylene, propylene and butylene which may be rectified in a device (not shown) between additional separating device 6a and 13.  The petroleum coke formed may be stripped off the original coke by steam blown in at 10.ALSO:Liquid hydrocarbons are converted to normally gaseous, partially unsaturated hydrocarbons by a process in which a granular heat-carrying mass is circulated through a closed system including a reaction zone, a re-heating zone and an elevating conduit, said mass being heated by indirect heat transfer in the re-heating zone, a liquid hydrocarbon to be converted is applied to the heated mass and the heated mass is passed through the reaction zone at such a rate and at a temperature <PICT:0790043/III/1> between 500 DEG  and 750 DEG  C. that the hydrocarbons are primarily converted to gaseous and minor quantities of liquid hydrocarbons which are conducted to a rectifying or gas separating device and are completely or partially discharged therefrom, the other part being used as a lifting gas, and secondarily to a coke layer on the mass and the mass is recirculated through the elevating conduit by means of the lifting gas or by means of one or more components thereof.  The initial liquid hydrocarbon may be petroleum oil, a fraction of petroleum oil, a residual oil or a bituminous tar oil.  The lifting gas may be ethane, propane or butane.  In an example, coke of globular form and a size of 5-15 mms. diameter is circulated at a rate of 1-7 tons per hour at a temperature of 640 DEG  C. in a mixing zone, 110 kilograms of crude oil are injected per hour.  The temperature of the coke is thereby lowered by about 80 DEG  C.  After 30 minutes the coke is elevated by the reaction gases and is again brought to the initial temperature by indirect heating.  The gaseous products leave the reactor after a dwell time of 20 seconds, while the coke produced deposits on the circulating coke.  A suitable apparatus consists of a separator 6 from which the heat carrying mass passes through the heater 1 and is mixed at 8 with the preheated oil in the reactor 2.  Cracked gases leave through outlet 9 and are fractionated in the rectifier 16.  The saturated low hydrocarbons are returned to the cycle at 13 and the remainder withdrawn at 12. The saturated low hydrocarbons may be used as the lifting medium where they are cracked in the tubular conduit 5 owing to contact with the hot coke to give unsaturated hydrocarbons such as ethylene, propylene and butylene which may be rectified in a device (not shown) between additional separating device 6a and 13. The petroleum coke formed may be stripped off the original coke by steam blown in at 10.